Utility of mobile, field-based artificial streams for assessing effects of pulp mill effluents on fish in the Canadian environmental effects monitoring (EEM) program

Abstract

Although the utility of artificial streams(mesocosms) as research tools for assessingeffects of contaminants on aquatic biota hasbeen recognized, their use in regulatoryprograms has been limited. We conducted threestudies to examine the utility of using mobile,field-based artificial streams to assess theeffects of pulp and paper effluents on fish asrequired in the Canadian Environmental EffectsMonitoring (EEM) program. When evaluatedagainst criteria of environmental relevance,interpretability, scientific defensibility, andcost-effectiveness, mesocosms satisfied allcriteria. Measured endpoints on fish survival,energy use (growth, gonad size) and energystorage (liver size, condition) were relevantto the detection and quantification of effluenteffects on fish. Response patterns were similarto those reported in the literature for fieldsurveys showing reduced gonad size andincreased liver size in adult mummichog (Fundulus heteroclitus) and decreased growth ofjuveniles. The flexibility of the systems tomeasure effects in multiple, replicatedtreatments under controlled effluent exposureand ambient conditions of water quality,temperature and photoperiod provided data thatcould not be obtained at these sites usingfield assessment approaches. The repeatabilityof using the same mobile, mesocosm system ofuniform design and operation at different millsites and for different receiving environmentswas unique and contributed to consistentscientific evaluation and interpretation. Thesestudies demonstrated that mesocosms producedgood quality data that fit within the requiredregulatory context of the Canadian EEM program.